SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a12a9c2ad6bbd2bd5621ca285fe177bc251d0e192ada4c61ad5141031f8c923b' 
  AND token = 'hNqfL0g3zMdci71ijhUhGiS7526ecxvkLwKmzThkMIk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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