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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b4a21ef5d2158c39fc5bae33642799452760b62cdbb1f13a5eb355ad76ce27a4' 
  AND token = 'v+kZfQ/CBT6plT5/FCIKPNG926oIUf0Xky9frqHeXFQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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