SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c1bc3317eff08200b1f0e1d18213106403cfe23571e24e225a4647d71d82d7ab' 
  AND token = '9S0AZuwtwQ7HqOg3Y0omsJVsBJQBYTO/+jFB7gIGnwU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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