SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '03b764d4097a67a6272af8758ef7195ebcc302f6295bc34df0c1a6c983449629' 
  AND token = 'DFiZhwO123BfAs4G07mVKAog4XVLgj0Omt2UPqZjlNQ=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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