Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'b1fbf8fe79e3ddc7acd594e675c067e49c2ad47fdf44c95207ca9ba44dda0f52' 
  AND token = 'nmA+spRA01mpuCbPt9PtAzzqoY9Ev4w4XGYVvT3DTq0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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