SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4a174577e550ceabe4c95edf81cdebece29ca365e25a1a09ffde816e142aae2a' 
  AND token = 'NXCb3fwRVblgLpuH4pIIh6vOugBGsCxgXzisjVlXh+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00039

JSON explain

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