SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9628f17c3478ca4dd4143bac6df719a8f84fb53adfb469011ec5a44ba4c8ad8' 
  AND token = 'gydvVyPPw8annZMkZyvL4E8rZZG0GGB7bOAi6elv4Zk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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