SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '941a391cb476e5635b5a8dce3b426f2c41e791fa0b345031bbb20e16d36e2f23' 
  AND token = 'wcMtqtmhCfqplYkAnMXrQRmFmKDMNfCWhyGYdXqeAsE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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