SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '89f2fade761c8d695f33946b685703a6be368b29e453903d9f662a0159dc8955' 
  AND token = 'QQ7h4KUsvxJuSky5H3e78gYLFN/JhceqMvKFKHSuDVE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00048

JSON explain

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