SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3b86986cf22db3ff201e616c37a8ca6f57d0902092e65d87aae36aff8500154c' 
  AND token = 'L+6Mm6RZChjOBwivR/xTFqFtH6BLis7wAHqRwJEbPzQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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