SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1f158b5500383714fbb147ae28835143177f86dc86936387975e51cb098fefe4' 
  AND token = 'C/KXSYXCLxWys/3BxV7HEq7Ja+wy801zb53zICAoHlU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00028

JSON explain

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