SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a25a66c78ac111a8db71d4cbc63da7ac428dd418f8c657ba7e05e7ca7fda8544' 
  AND token = '5bkyjRZZ2PlNEhCMRospyF7aKMmhSQa7/PqNfhgftNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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