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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c7b1aa8a2f6d7cb6ef132608169d414ccb41597d1dddecc5c467907d61a97991' 
  AND token = 'CIGO/Bp9DyYEMtdbIUwI3fgWLuLKXbQ0ebmjua91ffA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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