SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '20bc73a63dc98b382921b2f0a8c7e5fb97516acbccf9243f459b465bfefe1684' 
  AND token = '0L2lG1BBAoZ9g7Rzk7FIgSFKaqmDuezYwBu9ztzPxik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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