SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0850bea99d5667aca29aac40ea559d3b9bd52c53cf6ea8bc717758a4569beef7' 
  AND token = 'W+Ob36rTzgfWVsBwS0UyUaaAiSD36xVSf++si2mFu8A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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