SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9a7216a93125b14a82a0e94536326457771d56716a189618a8f3fab0127738c9' 
  AND token = 'gE9bUzgxrb3kqw+mNMk7I47y54hI2oZoPBurKNE4rZM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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