SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7cc40319c5b352be3a6507507a12871db4726a12bbc9910ca48ee89d31416e9d' 
  AND token = 'KaqqdjyEOi/IBtE6M0RnpVoFqzLKUU/gtyG9SjidxvQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}