SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '31a0fac9f960bde67527c25bc741f06aeaf8703fa6f08ac2ee6da326edf642ab' 
  AND token = 'Phesuq4f6H+TEwI3zEDmirBZeB5+72UZPWM6wQjPoQM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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