SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a5cd9d00383a0e856a76b967bef14505d107e7fde5c0bb76a0aeb68a2cbe5b53' 
  AND token = 'IxZJGcarylZgjXVR+glJPfhEasyumWhkiQBDboVRXng=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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