SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a1836a8a7290c8f7ebf18317ff865e5e49675c3d06491243d1e4bcc059b70f2' 
  AND token = 'ED+5BXupRD+U4FRKpxyoNKJZ2SCcFzXOWqd+IVAAboI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00040

JSON explain

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