SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1c994994d5f569099e5013e146cefabbadcdba07790014a00ceac373de6f7354' 
  AND token = 'InRJ2PZUglvKAe+aSS8MRW7hTGp0xrJz03U/sTykMgY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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