SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'dab622e874978dc960eec045d5801be62ddac5e10c03eb4d002e0e34f1f06806' 
  AND token = 'C61FyDRR5Dc7l8TBhrKlsKlznd4rQZ2mULXUOJJ+D/k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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