SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6ca525723a64477fea9dba85568068e520fdb7ceeb18717b950872f7e2eb1a20' 
  AND token = 'bVrPYVY3TxzJOjXyvLuW8RvuHbRVvG8Zx1X4cejE9MY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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