SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7bff9ee6165e9c69c2a2b96f69446c6de0bf416d3b14697936a17938a3fa4896' 
  AND token = 'H3bu1IFwwMYVMgb92vVwIZRcjlLu8/xqITD7tiJ+hw4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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