SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e86b53af05406ff06cbe1b0388c044da480cefaba3547be96e1b0df4641ddbb5' 
  AND token = 'Ej+Swc5b/nThj/lZTW3FG1fNlER1RgBPtGaDlhIqfCU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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