SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '217d7b9e88b68630d8db93c43f0c5f44137e6c8c5b69020c354cc792753add8d' 
  AND token = 'qfl8iY9TzBTTAGMmsJVv4j9UIgKrs8haBcFtAQS6mnE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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