SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '71fd943571e0613286a19494546aed50636d3a3170c8d76c6a6c5a57619e17ba' 
  AND token = 'y1AA7QwICkqoFJCML6j4sO54CYia7uQB0yacpPv9oq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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