SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1b549aed45cf35b4edcb5394caeecdf15f95c69f26c134df3d7f34085b8a9f89' 
  AND token = 'dPZSkzrDEQQuGwkLGKqCKopBFqnyyLKG7R4csz6Vfls=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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