SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5f1f1b9e255017acbdeb921143fc7fa37be03b6c5a0a147f869cd6d0a48666c' 
  AND token = 'w3JP7OrMQZgmbK7t2hHGsTNumVn/g3S3Ytj9NvySop4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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