SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0604856b814bd2e712a0bde06f1f8a92d2010c7887e6001f301b12d8138129e5' 
  AND token = 'Jvr7WqjP+uFHd8LApR7qBPs4eMOQFdH+F8nMIronlS4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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