SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '258470dff2016609d85d2e54bb5a7a5ad0db9eabf0a3bb92f3f83810d30dac13' 
  AND token = 'PbVrMkIUd9hpu1cydlIUQV2YZSoMgrdBkJtm1LfGi5k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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