SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '88fd7f4f1c5ebaa146c9c979010da8419d45bdf891457e2920f7b1c6d0680358' 
  AND token = 'e23kQYypbZ+ihwwpVm6HaYpCIBO/LrjL3csl1ACsFXc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00037

JSON explain

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