SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'aa5077b829ae2a5778a3e36b4e2297b7cf1df89bcb483b9477b1f919cc72aa55' 
  AND token = 'BilC3UDnAqQBvCMQQlLnxvzlxjoHlEt6jTXGzu5IfWw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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