SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'eba605c2a4d04f567639e1f7dcabf927d9321d60148852ab61b1716d575cd8e2' 
  AND token = 'BGMTH6jMT5hpQBggzSBLv3bQn+wDfzWoXY7p/aKqD2o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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