SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9d0bc9e73439db71e78b56afcb821413b060df99cd7498cf8e26885a3f9c8ac8' 
  AND token = 'RzIg7pMZYuxDrvyjfULXuEdJqMM2okGWSQv16tC3W+w=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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