SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cfe75750cc22219ddd4258edca5a873059d7d0665fe2b8057f97786a0beae9ca' 
  AND token = 'jqu1v0CrpatGdWOSmB36E+D/2PQtwnLWUTeGmPZnag4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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