SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a64d8edea5e0a12f2c867a781f1aae9aef004c3d2044c68d742c42d5a5eae7d8' 
  AND token = 'GFlXKZMDQv/9IZ4Ma8KRzp40ZGbZgZSjeM2rkUwA7Rs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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