SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89b463164edc5bf17d5dcef461cccb8fa078cb1638fc9e98bb3727c0953c6510' 
  AND token = 'bIJSTtswFFLebZe4ZDld77fztWLinIW6MohtkPEBYXY=' 
  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"
    }
  }
}