SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '354c4fda8f5f5383de9ecb256abcfc6dc26b2536697886a03171a692db2c93fb' 
  AND token = 'yY8rFWrHQyyM8wQPdu+wh/utdzahZN7tZYLbhLl0rf0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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