SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ecb290da88411199ce0a6a35276dc5ffd7db9ed64ec49738c211903665f12aca' 
  AND token = 'tb7XIf1V4pObkYkwTJMkKNqC5gJdjeepYd23T0Iwbms=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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