SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0126d55d71b41979957a232f05b56770af820be9b7e04d833dd13775434d258f' 
  AND token = 'j7F7T8Q0YalYwe23Yr5l+THmJmzpYSCDGxeLht5clhk=' 
  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"
    }
  }
}