SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '868caa331aeb1a9a44081748c20beb674de04560cadc2723532d6f15de141208' 
  AND token = '9Oq9RYIDB6aowkWrLVZRe/c0aOaRqfmD08J26IMnTNk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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