SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ed9cf7661db710e9ee9dcc7c0c8f0e5aaeeca5e40d213ac2cb86a35dcd58f6be' 
  AND token = 'FDqHKoSwKWO0Bmiigsa/ktR55XRM7REWvD2FlO2vxaU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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