SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '510be525224d5f461ae7ac5b580619b21b460fffb4e418ccbba433f985ffa1c9' 
  AND token = 'MjGVHmo7EwzCjl42C0jxdxlkJsgFKGqzdJv9KlwMMeU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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