SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f5f41a808954c111abc19418e24960462de0ab020e985fe9ee014cb79efd23c5' 
  AND token = 'o9GO00Cq6d9uEz3Z31wDh6rwKDugPJouqtdnlrl6a8w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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