SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd7b474617ef1c23ae964829e60f4bcca7dc5af7b8022fabec483437919045350' 
  AND token = 'NceLxJwu+8yhwWbttmUxFCGAEjCYqXO4Peh0J2ZmnRo=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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