SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '5d436e7f5fe1a2baba04f380decd2ad39ff7848cb02497a07f8aacf7ce5d8f47' 
  AND token = 'IayREFdm9Yb2BwYZsOd/VThxaTpTAQET218MVE42vLk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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