Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd12a520fc7026644247d6eb0c912889c13076577b3a1b0e2bc5fa5b827d4db72' 
  AND token = 'z+Hd2QxAOhRVk/HMkxx6Weo1EMXjmZfO8SCTxpLUPJ0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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