SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48ad55143399b1e27a76b010e5c2611df56a09075f37f760df9bc6241896c63a' 
  AND token = 'RDcJykCPvYpfTgP4dJMPBtHUb/NuxulGjVWN5XQF55E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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