SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e7822e7d73b98dc6695847f20c2a5d5b37e43bb2026e24fcff918e3c037d43a8' 
  AND token = 'EtNaLGiHf3/K0LHCI7Z/q9WV4S7Ywg5chOKTDkYrj9A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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