SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f432cafc84600cfe1157c5079d8bfb87e00036fd7bae135c43d66aff53280a48' 
  AND token = 'YLqxsT7kiWEP/apXPZCJ15XbLT7jKZ002dKWDQ/HxkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00046

JSON explain

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