SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8d0f0ef32aadef8cec4fdf1276eafc6f363e48885f4491130bb4ec149febf256' 
  AND token = 'NRNIQB1nwmJ0iEjOQHTmmgRhoKushp5hRqjT+dwk/B8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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