SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6fe90827e08253bf70a18398de7c422ea248eae58f600e2ffe5e699ebda428d6' 
  AND token = 'LoPr7GnD6mlPsjzkw4wj8XDOJAizjTr3x9eL9s5wil4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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