SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c25f5573e091645bd4986cec824002ba5c8062fa8fc09f7ab16f448f98f6b934' 
  AND token = 'NnBboD0UwRYeXzXHWY/Ow9KxCj26fR/YXa0rbUn15es=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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