SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c045baac51dd89fb39f78d29dacad8fa56f0490162866d974b207fd371684241' 
  AND token = 'mFPdnrhfRrYXWariOWiOweqwXZImdGGvGg/HPjX40rY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00038

JSON explain

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