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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f831e8bbe37cb998ba055a2801d788e4439e3e6e8450db84393f6f3da78cd5c3' 
  AND token = 'hKKQseAGA2C9JLVzAuEdF4w1K/4zNtDmPqj/qCeVj9E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}