Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9d8dfb5f2e65bb7203d70cc619723b6c8690042fd247f83ff9c0d163f7002d4' 
  AND token = 'aTZ0UlB83Se4GiLC5F9XugFVtxj8mTj+4ZA9SjNfk7Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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