SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'b2a92f45a161835c1a974df202f58914a43a2253fd381f75556a60897fafb6db' 
  AND token = '7FGmY8++d7t+KTQ4DEFvk2WgXn2nb5/C2ETQzzDnBM0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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