SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '86816d6f1adb3c0cee524f3507fc33ebeef6a61183818cb66ef99d7ef9dc7466' 
  AND token = 'ReGzDcfsO9c1ar6OLdLV8W1ZmXVEiro78s7pK8mv+sQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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