SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '20882f0d22d964470486be5e6defa401f695623bb3c6878b44c242d0f35f9077' 
  AND token = 'BNC7GObkT6AqtJM5hImzwHF5HwERRtN+TB7BWF1Uk3s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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