SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '169f6700cf8303ca86be8788a20727a8402266c9321483d74935f7dd11b9a813' 
  AND token = 'CSVWV//Fk4y1rGRzN0+Bu5bSolNzFcFPa8SFRQOoXkg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00070

JSON explain

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