SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '77f5d3d91db63419bc8e942e72e19c506cae6ab17a0434bc05abc8e8118522fe' 
  AND token = '/m360Oa4Z+iQlRu/Eum1x2HjTlJfqqPCuoVrdMfV5Sg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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