SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34fa1a2b75b2c24c157395cddd45fe4dfada49a807f2333626f5ecf548828f61' 
  AND token = 'omgW0QsqcRdCVS5eMf0vgq4L89h47DRZ9VuMPh1RZqI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}