SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4764220085fcac278adbc33ab77a5aeb54935fdc7dc410a2b5a5dd3e259fe39b' 
  AND token = 'LbEmvDOasMRnUSeU1Gdh3v2YKPCSgWmaBGbOxVpCtwY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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