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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f340ee72ee25e81948a538fd7f037730c6dad86fdb99e1d9735aa2c6ebb8f3e4' 
  AND token = 'ypUS5dcTHo+PSnDcEcfOQEwAe4SIcAqUnu/ACEZNTGk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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