SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e33052ea7c58fad35bf6afacb43db523758d690c4d5638d6a7b8adaa332aa567' 
  AND token = 'C2OYufQ6KIMdT53y+L7geuzF+kfsZ1EfKtIJgZZ85SI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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