SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '706399f06fba26ac735ae212da0091927e47036f3fed3411f318264213975cdc' 
  AND token = 'kxjGeRVk7ZJiWD/Ld8j7c/q+WaFihW/6qmIlxseQJuI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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