SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a619e414beb1303bd0ef24fad4b69c9e912048adc51fce925d8082a6a9695b7b' 
  AND token = 'Cku2PI95TRY1bbNWVjv4ZscPGFtZnyvF5sL5P2fyj7k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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