SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd0bb18c55a2be9c4d8a578610eb46cecf4c40249a356aafb6ad3af898a43b860' 
  AND token = '9O1VYwYpzqOpZItRFSHXK2/YVeNJRICjosBLqEpz41M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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