SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7336e151553c809e0a6221aae945e3970d0a6e19f24ba56fefbfcdeb6a8a7199' 
  AND token = '5zsDiCnafrn4UC/XeEVHLbZQKboTXn6BuaiPOfFlxkw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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